Effects of various chemical and physical agents on developing nervous system of rodents will be studied. (1) Inhibitors of cholesterol biosynthesis will produce numerous intracytoplasmic inclusions in neurons and other types of cells in CNS, the feature resembling human lipid storage disease. Also when the inhibitors were administered at time of myelination of CNS, selective degeneration of oligodendroglia is observed. Chronological changes of these lesions will be studied. (2) Effects of psychosine in developing CNS will be studied. Preliminary study showed that it produced severe hemorrhagic lesions in CNS when it was administered intracerebrally.